Usage
Poractant alfa is a pulmonary surfactant primarily used for the rescue treatment (and prophylaxis) of Neonatal Respiratory Distress Syndrome (RDS), also known as hyaline membrane disease, in premature infants. It can also be used for other conditions where surfactant deficiency is suspected, such as severe Meconium Aspiration Syndrome (MAS), but specialist consultation is recommended in such cases. It belongs to the pharmacological class of lung surfactants. Poractant alfa mimics the action of natural lung surfactant by reducing surface tension at the air-liquid interface in the alveoli. This prevents alveolar collapse during expiration and improves lung compliance, facilitating gas exchange.
Alternate Names
- Generic Name: Poractant alfa
- Brand Name: Curosurf®
How It Works
Pharmacodynamics: Poractant alfa replaces deficient or dysfunctional endogenous lung surfactant in neonates with RDS. It reduces surface tension within the alveoli, preventing their collapse during expiration, thus improving lung compliance and oxygenation.
Pharmacokinetics: Poractant alfa is administered intratracheally and rapidly adsorbs to the alveolar surface, forming a monolayer at the air-liquid interface. It is absorbed from the lungs and is likely metabolized and cleared similar to endogenous surfactant. The exact pathways have not been fully elucidated in humans, but likely involve alveolar macrophages, reuptake into type II pneumocytes, and clearance via lymphatic and vascular pathways.
Mode of Action: Poractant alfa works by mimicking the function of natural surfactant, which is composed of lipids and specific proteins (SP-B and SP-C). These proteins help to organize the lipids in the surfactant monolayer so it can reduce surface tension more effectively.
Dosage
Standard Dosage
Neonates: The initial recommended dose is 2.5 mL/kg birth weight (200 mg/kg phospholipids) administered intratracheally. Up to two repeat doses of 1.25 mL/kg (100 mg/kg phospholipids) each may be administered approximately 12 hours apart if the infant remains intubated and RDS persists or worsens. The maximum recommended total dose is 5 mL/kg (400 mg/kg phospholipids). For prophylactic use in premature infants at high risk of developing RDS, a single dose of 100–200 mg/kg phospholipids is given within minutes after birth.
Adults: Not applicable, only used in neonates.
Special Cases:
- Elderly Patients N/A
- Patients with Renal Impairment No dose adjustment necessary.
- Patients with Hepatic Dysfunction No dose adjustment necessary.
- Patients with Comorbid Conditions No specific dose adjustments are mentioned, but clinical judgment is necessary.
Clinical Use Cases
- Intubation: Ensure proper endotracheal tube placement and patency prior to Poractant alfa administration.
- Mechanical Ventilation: May be administered during mechanical ventilation without interrupting it if using a dual-lumen endotracheal tube with medication administration lumen.
- Intensive Care Unit (ICU) Use: Common in NICUs for managing RDS in premature infants.
- Emergency Situations: Used in emergency situations in neonates with RDS or severe MAS.
Dosage Adjustments
- No specific dose modifications are required for renal or hepatic impairment.
Side Effects
Common Side Effects
- Transient bradycardia
- Transient hypotension
- Oxygen desaturation (transient)
- Endotracheal tube blockage
Rare but Serious Side Effects
- Pulmonary hemorrhage
- Pneumothorax
- Infection (sepsis, pneumonia)
Long-Term Effects
- Bronchopulmonary dysplasia (chronic lung disease) has been associated with the use of surfactant but it’s difficult to distinguish from the complications of prematurity itself.
Adverse Drug Reactions (ADR)
- Acute deterioration in respiratory status (requiring immediate intervention)
- Severe bradycardia or hypotension
- Signs of infection (fever, lethargy, respiratory distress)
- Signs of pulmonary hemorrhage (blood in the airways, sudden desaturation)
Contraindications
- Known hypersensitivity to poractant alfa or any of its components.
Drug Interactions
- No clinically significant drug interactions are specifically noted. However, consider other interventions or medications that may impact the respiratory status of the neonate.
Pregnancy and Breastfeeding
- Pregnancy: Poractant alfa is indicated for use in premature neonates, making pregnancy itself irrelevant.
- Breastfeeding: Not applicable as the medication is administered intratracheally to neonates.
Drug Profile Summary
- Mechanism of Action: Replaces deficient surfactant, reducing alveolar surface tension, improving lung compliance.
- Side Effects: Bradycardia, hypotension, oxygen desaturation, endotracheal tube blockage, pulmonary hemorrhage.
- Contraindications: Hypersensitivity.
- Drug Interactions: None specifically identified.
- Pregnancy & Breastfeeding: Only indicated for neonates.
- Dosage: 2.5 mL/kg birthweight initially, up to two repeat doses of 1.25 mL/kg.
- Monitoring Parameters: Oxygen saturation, heart rate, blood pressure, respiratory rate, signs of infection and pulmonary hemorrhage.
Popular Combinations
- Often used alongside mechanical ventilation and oxygen therapy in the management of RDS.
Precautions
- General Precautions: Administer only by trained professionals experienced in neonatal resuscitation and intensive care. Ensure proper endotracheal tube placement and patency. Stabilize the infant’s general condition before administering. Closely monitor oxygenation, heart rate, and blood pressure during and after administration.
- Specific Populations (Neonates): Careful monitoring is essential due to the potential for rapid changes in respiratory status. Adjust oxygen and ventilator settings accordingly.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Poractant Alfa?
A: The initial dose is 2.5 mL/kg birth weight, followed by up to two repeat doses of 1.25 mL/kg every 12 hours, as needed.
Q2: How is Poractant Alfa administered?
A: It is administered intratracheally via a catheter inserted into the endotracheal tube or through a dedicated secondary lumen of a dual-lumen tube.
Q3: What are the common side effects of Poractant Alfa?
A: Common side effects include transient bradycardia, hypotension, and oxygen desaturation, usually managed with supportive care.
Q4: Are there any contraindications to using Poractant Alfa?
A: The only known contraindication is hypersensitivity to poractant alfa or its components.
Q5: Can Poractant Alfa be used prophylactically?
A: Yes, it can be administered prophylactically to premature infants at high risk of developing RDS, typically at a dose of 100–200 mg/kg within minutes of birth.
Q6: How should I monitor a neonate after administering Poractant Alfa?
A: Closely monitor oxygen saturation, heart rate, blood pressure, respiratory rate, and observe for any signs of infection or pulmonary hemorrhage.
Q7: How long should I wait before suctioning the airway after administering Poractant Alfa?
A: Do not suction the airway for at least one hour after administration unless there is significant airway obstruction.
Q8: What are the signs of a serious adverse reaction to Poractant Alfa?
A: Signs of a serious reaction include severe bradycardia or hypotension, signs of infection (fever, lethargy, worsening respiratory distress), and pulmonary hemorrhage (blood in the airways, sudden desaturation), requiring immediate medical attention.
Q9: What is the maximum total dose of Poractant Alfa that can be given?
A: The maximum total dose is 5 mL/kg birth weight.
